DNA, Repressor–Operator Recognition

Abstract

Transcriptional control is the most important mechanism of differential gene expression in the vast majority of organisms. Repressors control transcription by binding to specific sequences (operator sites) in genomic DNA and sequestering those regions from RNA polymerase, hence preventing transcriptional initiation. Repressor–operator binding is controlled by the physiological state of the cell, either directly by changes in the active repressor concentration or indirectly by sensing of the levels of key metabolites. Operator binding is highly specific and is achieved by a large number of distinct molecular interactions. A combination of structural studies and molecular genetics has led to rapid recent progress in understanding this field. Repressor–operator interactions provide simple tools to regulate the expression of recombinant proteins in a variety of organisms such as bacteria and yeast.